Hereditary sensory neuropathy type 1 (HSN1, MIM 162400; ref. 1) genetically maps to human chromosome 9q22 (refs. 2-4). We report here that the gene encoding a subunit of serine palmitoyltransferase is located within the HSN1 locus, expressed in dorsal root ganglia (DRG) and mutated in HSN1.

Germination and growth of spores of butyric acid bacteria (BAB) may cause severe defects in semihard cheeses. Silage is the main source of BAB spores in cheese milk. The objectives of the study were to determine the significance of grass silages and corn silages as sources of BAB spores and to investigate the relationships between high concentrations of BAB spores in corn silage and aerobic deterioration. In the first survey, samples were taken from various locations in silos containing grass and corn silages and from mixed silages in the ration offered to the cows on 21 farms. We demonstrated that the quantity of BAB spores consumed by cows was determined by a small fraction of silage with a high concentration of spores (above 5 log10 BAB/g). High concentrations were most often found in corn silage within areas with visible molds (69% of the samples). Areas with visible molds in grass silage and surface layers of corn silage contained, respectively, 21 and 19% of the cases of concentrations above 5 log10 BAB spores/g. Based on these results, we concluded that currently in the Netherlands, corn silage is a more important source of BAB than is grass silage. In a second survey, 8 corn silages were divided into 16 sections and each section was studied in detail. High concentrations of BAB spores were found in only the top 50 cm of these 8 silages. Elevated concentrations of BAB spores were associated with different signs of aerobic deterioration. In 13% of the sections in corn silage with more than 5 log10 yeasts and molds/g, more than 5 log10 BAB spores/g were found. Sections with a temperature of more than 5 degrees C above ambient temperature contained, in 21% of the cases, more than 5 log10 BAB spores/g. Concentrations above 5 log10 BAB spores/g were measured in 50% of the sections with a pH above 4.4. All sections with a pH above 4.4 also showed a temperature that was more than 5 degrees C above ambient temperature and a concentration of yeasts and molds above 5 log10 cfu/g. Based on these results, we postulated that high concentrations of BAB spores in corn silage are the result of oxygen penetration into the silage, resulting in aerobic deterioration and the formation of anaerobic niches with an increased pH just below the surface. Growth of BAB in these anaerobic niches with an increased pH caused the locally high concentrations of BAB in corn silage.

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The authors examine the social constructionist nature of solution-focused therapy. The therapy's components are illustrated through the presentation of a first-session conversation between Insoo Kim Berg as therapist and a 19-year-old mother, who states that she is “stressed out and depressed.” As the conversation develops, the young mother's sense of herself changes and the integration of the therapy's components become apparent. Next, existing outcome research is reviewed. Although descriptive in nature and limited in scope, research suggests positive outcomes for diverse clients and presenting problems. Finally, several connections are made between solution-focused procedures and social constructionist theory: the social construction of reality, language as the medium and substance of meaning, client change through the construction of new meanings, the client as expert, taking a collaborative stance, reflexivity, drawing on client strengths, and solutions as co-constructions.

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Control of contamination of farm tank milk (FTM) with the spore-forming butyric acid bacteria (BAB) is important to prevent the late-blowing defect in semi-hard cheeses. The risk of late blowing can be decreased via control of the contamination level of FTM with BAB. A modeling approach was applied to identify an effective control strategy at the farm level. The simulation model developed was based on a translation of the contamination pathway into a chain of unit operations. Using various simulations, the effects of factors related to feed quality, feed management, cattlehouse hygiene, and milking practices on the contamination level of FTM were evaluated. Contamination level of silage was found to be the most important factor. When silage contains on average less than 3 log10 BAB/g, a basic pretreatment of udder teats before milking (approximately 75% removal of attached spores) is sufficient to assure an FTM contamination level below 1 BAB/mL. When silage contains more than 5 log10 BAB/g, it should not be fed, because it then becomes almost impossible to assure an FTM contamination level below 1 BAB/mL. Measures aimed at improving cattlehouse hygiene, the contamination via soil, and the contamination level of other feeds contribute only marginally to the control of the contamination of FTM with BAB. Application of the modeling methodology could be beneficial for the control of the contamination of FTM with other microorganisms such as Bacillus cereus.

A year-long survey of 24 dairy farms was conducted to determine the effects of farm management on the concentrations of butyric acid bacteria (BAB) spores in farm tank milk (FTM). The results were used to validate a control strategy derived from model simulations. The BAB spore concentrations were measured in samples of FTM, feces, bedding material, mixed corn and grass silage fed to cows in the barn, and soil. In addition, a questionnaire was used to gather farm management information such as bedding material used and teat cleaning method applied. The average BAB spore concentration in FTM was 2.7 log10 spores/L, and 33% of the FTM samples exceeded a concentration of 3 log10 spores/L. Control of the average spore concentration in mixed silage fed was the only aspect of farm management that was significantly related to the concentration of BAB spores in FTM. Farms that fed mixed silage with the lowest average BAB spore concentrations (3.4 log10 spores/g) produced FTM with the lowest average concentration (2.1 log10 spores/L). The efficiency of farm management in controlling the BAB spore concentration in FTM depended to a large extent on the ability of farmers to prevent incidents with elevated BAB spore concentrations in mixed silage (>5 log10 spores/g) and not on the average BAB spore concentration in mixed silage across the year. The survey showed that farmers should aim for a concentration in mixed silage of less than 3 log10 spores/g and should prevent the concentration from exceeding 5 log10 spores/g to ensure a concentration in FTM of less than 3 log10 spores/L. These results correspond with the previously reported model simulations.